The invention relates to valve assemblies for fluid-containing vessels, such as pressurized vessels. More particularly, the invention relates to valve assemblies for controlling the filling of such pressurized fluid vessels.
Various valve assemblies constructed to avoid overfilling of pressurized fluid vessels are known. In U.S. Pat. No. 5,282,496 there is disclosed a two-way valve for filling and draining a gas cylinder. The valve assembly includes a float assembly for control of the opening and closing of the valve as a function of the fluid level in the tank so that the valve can be closed when the fluid level corresponds to the predetermined safe capacity of the vessel.
U.S. Pat. No. 6,076,546 discloses an overflow protection valve assembly in which the valve plunger is separated from the fluid flow to prevent premature closing due to the pressure on the valve plunger.
Applicant's U.S. Pat. No. 6,293,302 discloses a simple valve assembly having a float arm and movable valve body supported on a valve stem disposed to move in and out of a flow path under the action of an actuating member driven by a float which acts directly on a lower end of a valve stem. The valve assembly finds particular applicability for use in liquefied petroleum tanks, such as propane tanks, where it is important from a safety perspective that the tank is not overfilled.
The present invention seeks to provide a further improved valve assembly which provides positive, reliable closure and yet is of simple overall construction.